From: David Miller <davem@davemloft.net>
To: brouer@redhat.com
Cc: netdev@vger.kernel.org, mkubecek@suse.cz, fw@strlen.de,
liujian56@huawei.com
Subject: Re: [PATCH net 0/2] net: revert lib/percpu_counter API for fragmentation mem accounting
Date: Sun, 03 Sep 2017 11:01:20 -0700 (PDT) [thread overview]
Message-ID: <20170903.110120.230269539906979454.davem@davemloft.net> (raw)
In-Reply-To: <150425790711.22227.12264977619066874632.stgit@firesoul>
From: Jesper Dangaard Brouer <brouer@redhat.com>
Date: Fri, 01 Sep 2017 11:26:03 +0200
> There is a bug in fragmentation codes use of the percpu_counter API,
> that can cause issues on systems with many CPUs, above 24 CPUs.
>
> After much consideration and different attempts at solving the API
> usage. The conclusion is to revert to the simple atomic_t API instead.
>
> The ratio between batch size and threshold size make it a bad use-case
> for the lib/percpu_counter API. As using the correct API calls will
> unfortunately cause systems with many CPUs to always execute an
> expensive sum across all CPUs. Plus the added complexity is not worth it.
Series applied, thanks Jesper.
prev parent reply other threads:[~2017-09-03 18:01 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-01 9:26 [PATCH net 0/2] net: revert lib/percpu_counter API for fragmentation mem accounting Jesper Dangaard Brouer
2017-09-01 9:26 ` [PATCH net 1/2] Revert "net: use lib/percpu_counter API for fragmentation mem accounting" Jesper Dangaard Brouer
2017-09-01 9:30 ` Florian Westphal
2017-09-01 9:26 ` [PATCH net 2/2] Revert "net: fix percpu memory leaks" Jesper Dangaard Brouer
2017-09-03 18:01 ` David Miller [this message]
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